Welcome to EDAboard.com

Welcome to our site! EDAboard.com is an international Electronics Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.

How 2 parallel 2+ 24LC256 EEPROMS

Status
Not open for further replies.

prinsloo

Member level 5
Joined
Sep 19, 2004
Messages
93
Helped
2
Reputation
4
Reaction score
1
Trophy points
1,288
Location
Bethlehem RSA
Activity points
697
24lc256 connect

Dear friends
Do you know how to parallel 2 or more 24LC256 serial EEPROMS?
I need a lot of memory to store data for a pic project
mk2 pic electric meter.

Thank you
 

sda

Member level 5
Joined
Apr 22, 2002
Messages
89
Helped
0
Reputation
0
Reaction score
0
Trophy points
1,286
Location
Greece
Activity points
819
24lc256 and programming

Parrallel the I2C pins, and configure your address pins (1-2-3) for different addresses for the 2 chips. You can connect up to 8 devices parrallel.

Cheers
sda
 

IanP

Advanced Member level 5
Joined
Oct 5, 2004
Messages
7,942
Helped
2,311
Reputation
4,624
Reaction score
531
Trophy points
1,393
Location
West Coast
Activity points
66,416
diagrama 24lc256

Or instead of using 24LC256s you can use 24FC512, 24FC1024 or 24FC2048 etc
Each one doubles the capacity of the previous chip and they also can be connected in parallel (SDA, SCL) in sets of up to 8 (A0, A1 and A2) ..
 

bobcat1

Advanced Member level 4
Joined
Jul 10, 2002
Messages
1,288
Helped
99
Reputation
198
Reaction score
34
Trophy points
1,328
Activity points
8,545
24fc512 using spi

Hello

Why are you using the 24xxx memory use the M25Pxx from ST or Atmel with up to 8 MBYTE of flash memory using the SPI serial bus

www.ST.com or google for M25P10

All the best


Bobi
 

prinsloo

Member level 5
Joined
Sep 19, 2004
Messages
93
Helped
2
Reputation
4
Reaction score
1
Trophy points
1,288
Location
Bethlehem RSA
Activity points
697
24lc256 with pic programming

Dear Friends
I can,t seem to find I2C pin.Pins marked are as follow-1-A0,2-A1,3-A2.4-GND,5-SDA,6-SCL,7-WP,8-+VE.(EPE mag Feb05).
I also need to change the PIC .ASM file to record to correct address of 24LC256,and I don't know how.File is to complicated for my little knowledge of PIC programming.
Regards
 

Cortex

Full Member level 3
Joined
Mar 26, 2005
Messages
182
Helped
12
Reputation
24
Reaction score
4
Trophy points
1,298
Location
Morocco
Activity points
2,733
24lc256 address pins

1-A0,2-A1,3-A2. are the Adress
from 000 to 111 so 8 Eeprom possible
 

prinsloo

Member level 5
Joined
Sep 19, 2004
Messages
93
Helped
2
Reputation
4
Reaction score
1
Trophy points
1,288
Location
Bethlehem RSA
Activity points
697
24lc256 programming

If I understand you correctly I must connect A1 to A1 to A1 FOR 3 chips together?How do I controll the writing to the chips-at present the program for the pic is set to 'roll over'
 

silvio

Advanced Member level 3
Joined
Dec 31, 2001
Messages
716
Helped
105
Reputation
210
Reaction score
16
Trophy points
1,298
Location
Romania
Activity points
11,470
24fc512 how to

prinsloo said:
If I understand you correctly I must connect A1 to A1 to A1 FOR 3 chips together?How do I controll the writing to the chips-at present the program for the pic is set to 'roll over'

No you have to connect in parallel only SCL and SDA line of each chip.
The A0, A1 and A2 must be hardware connected to +VE and GND.
See this diagram:
https://www.ucapps.de/mbhp/mbhp_lcd7_iic.pdf

Then you must use the control byte to address the chip.

What do you mean the program is set for roll over ?
 

prinsloo

Member level 5
Joined
Sep 19, 2004
Messages
93
Helped
2
Reputation
4
Reaction score
1
Trophy points
1,288
Location
Bethlehem RSA
Activity points
697
pic 24lc256

I quote 'memory is controlled by pic pins RC3(clock) and RC4(data).data is transfered serially in response to the clock signal.Data pin is bidirectional ...The memory is accessed cycliclly,recording to memory bytes from 0 to 32K,then rolling over to zero,and then recording over the previous memory locations,up to 32K again,and so on.To maintain program simplicity in respect of rollover point,the number of bytes for each sample has been set at the "round" binary number of 16,....At each minute interval two bytes for voltage are recorded,two bytes each for both current channels,with two bytes left over.To one of these is recorded a "flag"which indicates at what point in the memory count is set to zero and ignored.'
I have fig 5.1,down loaded from Microchip,and data sheet.Do I have to change the .asm file for the pic to know that it must write to a certain address?
 

prinsloo

Member level 5
Joined
Sep 19, 2004
Messages
93
Helped
2
Reputation
4
Reaction score
1
Trophy points
1,288
Location
Bethlehem RSA
Activity points
697
Is there nobody that can help me with my problem?Is it possible or just to difficult to change the .asm file?
 

Status
Not open for further replies.

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Top